The present invention relates to the art of hoist rings, which are generally used to secure a lifting device to a heavy load or object.
It is well known in the art that a hoist ring can be connected to a load member, such as a die set or mold, and then used to lift and manipulate the load member. Further, it is well known that a hoist ring attached to a load member can be used to secure the load member such as for transportation.
Fuller U.S. Pat. No. 6,068,310 is incorporated by reference herein as background information for hoist rings. Fuller discloses a side pull style hoist ring that pivotally secures a load bearing ring to a load member. Another style of hoist ring used to lift or secure a load member is disclosed in Schron U.S. Pat. No. 5,634,734 and Schron U.S. Pat. No. 5,743,576. The Schron patents disclose a center pull style hoist ring that pivotally secures a load bearing ring to a load member. As with the side pull hoist ring disclosed in Fuller, the center pull hoist ring provides rotation about two perpendicular axes, thus allowing the load bearing ring to extend pivotally toward the direction in which the load member is pulled. However, the two axes intersect, which is not true in Fuller. The Schron patents are also incorporated by reference as background information.
It is well known in the art that by securing a load ring to an object, the load ring can be used to lift or secure the object. In this respect, a hook attached to a hoisting device may be used to lift heavy objects, such as molds and die sets. In addition, straps or tie downs can be attached to the load ring to secure a large object during shipment. Earlier load bearing rings used rigid ring mechanisms attached to the load member, the common attachment method being directly threading the load ring into a threaded bore on the surface of the load member. This design had many problems in that by directly threading the rigid load ring to the surface of the object the load ring could become loose, which would require subsequent tightening of it. In addition, the bending moment produced when the lifting device moved the load member in a direction at an angle from the axis of the threaded bore required stronger materials and additional reinforcement of the load ring.
To overcome the shortcomings of the rigid ring, hoist rings that allowed the load bearing ring to pivot toward the direction of the movement without loosening were developed. However, additional components were required in order to allow the load bearing ring to pivot into the direction of the force being applied, adding to the expense of the manufacturing process. Further, to produce a hoist ring that allowed the load bearing ring to pivot into the direction of the applied force and act as a single component in both the mounted and unmounted condition, complicated support members were required to prevent the hoist ring from becoming disassembled while allowing for pivotal movement about two axes. Further, due to the substantial forces created by using a hoist ring, high strength materials are used for the support member and typically these types of materials do not possess properties favorable for machining. This further added to the overall cost of the earlier hoist ring assemblies.
In accordance with the present invention, an improved hoist ring is provided for securing a hoisting or retaining device to a load member in which the hoist ring requires a minimum number of components while still maintaining its strength, integrity and remaining in an assembled condition, even when uninstalled from the load member. In this respect, a hoist ring according to the present invention includes a load bearing ring pivotally retained by a support member, thus allowing the load ring automatically to adjust to the direction of the applied force although the hoist ring includes a minimum number of parts. By automatically adjusting to the direction of the applied force, the structural integrity of the hoist ring is increased, and by reducing the number of components therein, the cost of the hoist ring is decreased. Further, by having components that remain in an installed condition even when the hoist ring is unmounted, the components cannot be lost.
The foregoing advantages are achieved in accordance with the present invention by a support member that includes a bolt receiving passage and a transverse pivot pin passage, which passages intersect within the support member to allow the engagement between the load ring and the support member to retain the bolt within the passage. By using a pivot pin to retain the bolt within the support member, fewer component parts are required to produce the hoist ring according to the present invention. And by using the bolt passage and pivot pin passage according to the present invention, complex machine operations are not required, thus resulting in further reductions in the cost of the hoist ring. Even further, the transverse bolt and pivot pin passages according to the present invention allow for pivotal movement of the load ring about two axes, producing automatic adjustment of the load ring in the direction of the applied force. The foregoing advantages are achieved by a pin receiving recess in the bolt that engages with a pivot pin without inhibiting the pivotal rotation about the two axes.
It is accordingly an outstanding object of the present invention to provide a hoist ring assembly that pivotally engages with a load member to allow the load bearing ring to automatically adjust to the direction of the force being applied during the lifting or securing procedure.
Another object is the provision of a hoist ring assembly of the foregoing character that requires fewer components and fewer manufacturing steps.
A further object is the provision of a hoist ring assembly of the foregoing character that is less expensive to produce while maintaining its structural integrity.
Still another object of the present invention is the provision of a hoist ring assembly of the foregoing character joined so that its components are retained therein, even when the hoist ring is removed from the load member.
Yet another object is the provision of a hoist ring assembly of the foregoing character that enables a pivot pin to engage with the bolt to maintain the bolt within the passage of the support member without inhibiting the pivotal rotation of either about the transverse axes.